Improves JSON deserialization for product and stock picking models by
using custom `fromJson` methods and explicit `JsonKey` mappings.
This ensures robust parsing of fields like barcode, display name, and product IDs.
Adds a new `ecart` getter to calculate the difference between requested
and received quantities for stock moves.
Updates the reception details page to display a list of products
with their requested, received, and calculated difference quantities.
Removes redundant JSON-RPC fields from the `stock.picking/web_read` API call.
6e49971883